Geth hanging while syncing blocks(attached logs)

[gsj5]

System information

Version: 1.5.0-unstable
Protocol Versions: [63 62 61]
Network Id: 1
Go Version: go1.5.1
OS: Linux ip-172-31-11-69 3.13.0-37-generic #64-Ubuntu SMP Mon Sep 22 21:28:38 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux

Expected behaviour

geth continuously syncs

Actual behaviour

Taking hours at a time to sync next set of blocks, even with 25 peers attached

Steps to reproduce the behaviour

Ran geth with nohup, which initially worked as expected, however, after an hour, it stopped syncing blocks. Waited for 50 minutes without much joy, so attached to geth, and set debug.verbosity(6) to see what was going on. See attached logs of peer list and geth debug log for details.

Downloads.zip

BTW, numerous past attempts at geth --fast has not worked either.

Backtrace

[backtrace]

[d57heinz]

on 1.5.0 you have to completely remove all contents of the blocks folder in order for the --fast sync to work. at least in my experience. And im on windows 10 was something on the output about their being blocks found and then it would disable fast sync. cant remember exact details now.. I have had it corrupt the blockchain twice now.. Im back on a pool till its all sorted out. Best Regards

[gsj5]

@d57heinz, thanks for the feedback. Yes, I am aware of the explicit requirement to start fresh when using geth --fast.

I believe issue you're alluding might be similar to the one I reported few days ago at #2467. After getting "empty head header set", last block# is reset and few minutes later fast sync says its complete, and disables itself. Unfortunately, I haven't received any feedback on this issue and not sure if it actually is the root cause of my issues with fast syncing.

[silver84]

Hey guys
I'm experiencing the same issue

Version: 1.4.4 stable
Protocol Versions: [63 62 61], Network Id: 1
Blockchain DB Version: 3
OS: OSX 10.10.5

geth --fast
eth/handler.go:92] blockchain not empty, fast sync disabled
download few thousand block and then stop, then restart few hundreds than stop...
...restart to download few thousand and then I've got Synchronisation failed: peer is unknown or unhealthy or Peer 767df9f471999661 [blocks 0.00/s, receipts 0.00/s, states 0.00/s, lacking 0]: empty head header set...stop downloading...and then restart after a while
Any what can be the issue ?

[fjl]

The issue has been identified. Watch‎ #2569 for progress.